1. Field of the Invention
The present invention relates to a magnetic recording medium fabrication method and a magnetic recording medium fabrication apparatus.
2. Description of the Related Art
Recently, a magnetic storage apparatus may be provided in various products, including personal computers, video recorders, data servers, and the like, and the importance of the magnetic storage apparatuses is increasing. These magnetic storage apparatuses include a magnetic recording medium that magnetically stores electronic data by magnetic recording. Examples of the magnetic storage apparatus include a magnetic disk drive, a flexible disk drive, a magnetic tape apparatus, and the like. A HDD (Hard Disk Drive) is an example of the magnetic disk drive.
For example, a general magnetic recording medium has a multi-layer stacked structure including an underlayer, an intermediate layer, a magnetic recording layer, and a protection layer that are deposited in this order on a nonmagnetic substrate, and a lubricant layer coated on a surface of the protection layer. In order to prevent mixing of impurities between the layers forming the magnetic recording medium during fabrication of the magnetic recording medium, an in-line vacuum deposition apparatus is used to continuously stack the layers under decompression, as described in Japanese Laid-Open Patent Publication No. 8-274142, for example.
In the in-line vacuum deposition apparatus, a plurality of deposition chambers having a deposition means capable of depositing a layer on the substrate are connected via a gate valve, together with a chamber for carrying out a thermal process and an auxiliary chamber, in order to form a single deposition line. When the substrate is set on a carrier and passed through the deposition line, the layers are successively deposited on the substrate to fabricate the magnetic recording medium having the desired structure.
Generally, the deposition line is arranged in a ring shape, and a substrate loading and unloading chamber is provided in the deposition line in order to load and unload the substrate with respect to the carrier. The carrier, which passes through the deposition chambers of the deposition line, reaches the substrate loading and unloading chamber where the substrate having the layers deposited thereon is unloaded from the carrier. In addition, after removing the substrate from the carrier, a new substrate to be subjected to the deposition is loaded onto the carrier in the substrate loading and unloading chamber.
In addition, as a method of forming the lubricant layer on the surface of the magnetic recording medium, a vapor-phase lubrication has been proposed in Japanese Laid-Open Patent Publication No. 2004-002971, for example. The vapor-phase lubrication places the magnetic recording medium within a vacuum chamber, and introduces a gas lubricant into the vacuum chamber.
In a case in which the magnetic recording medium having the multi-layer stacked structure described above is fabricated by the in-line vacuum deposition apparatus, a vacuum deposition apparatus that carries out sputtering is used to form the magnetic recording layer, a vacuum deposition apparatus that carries out ion beam deposition is used to form the protection layer, and a vacuum deposition apparatus that carries out vapor-phase lubrication is used to form the lubricant layer, for example. Hence, the layer forming processes (or deposition steps) from the formation of the magnetic recording layer until the formation of the lubricant layer can be carried out without exposing a stacked body to the atmosphere, and mixing of impurities into each of the layers from the atmosphere may be prevented.
However, according to the in-line vacuum deposition apparatus that continuously forms the magnetic recording layer, the protection layer, and the lubricant layer on the stacked body, a process gas used to form the protection layer and a process gas used to form the lubricant layer have considerably different physical properties, and the effects on the layers formed by these processes may be large when the process gases are mixed, to thereby deteriorate the quality of the layers that are formed.
In order to prevent the quality of the layers that are formed from deteriorating due to the mixing of the gases having the different physical properties, it may be desirable to sufficiently exhaust the residual process gas remaining within the deposition chamber after the process to form the protection layer ends, for example. However, a relatively long exhaust time may be required to sufficiently exhaust the residual process gas within the deposition chamber, and the productivity of the in-line vacuum deposition apparatus may deteriorate.
Hence, in the conventional magnetic recording medium fabrication method and apparatus, it may be difficult to simultaneously prevent the quality of the formed layer from deteriorating and improve the productivity.